Overload current sensing electric controllers have been known heretofore. However, prior devices of this type have been of rather large size and weight. This is for the reason that the contactor or relay was enclosed in one housing and the tripping control circuit was enclosed in another housing which were separately attached to a mounting panel. The overload current transformer wound toroids were placed around the three-phase load conductors and connected to the tripping control circuit and the latter was connected to the relay by electrical conductors. This not only involved large size and weight but also required a rather large amount of panel mounting space.
While these prior devices have been useful for their intended purposes, this invention relates to improvements thereover.